You didn't specify whether you're asking about the .44 Magnum or the .44 Special.
The New Vaquero in .357 Magnum, .44 Special, and .45 Colt are built on the medium-sized frame and have the small steel grip frame. The .357 will weigh more because less metal has been removed from the cylinder and barrel for the smaller bore. It will also handle higher pressures and be capable of delivering more energy than .44 Special or .45 Colt in a New Vaquero.
I don't know if .44 Special New Vaqueros and medium-framed Blackhawks are or were factory-offered, but they are popular whether they're factory or aftermarket conversions. There are also .44-40's.
The .44 Magnum Vaquero is built on the large-sized frame (same frame as most post-'72/73 Blackhawks, and all Super Blackhawks). It also has the larger grip-frame, but that is aluminum and not steel like New Vaqueros. The .44 Magnum Vaquero, and all early Vaqueros should be capable of handling high pressures and "Ruger-only" handloads that can deliver far more energy than SAAMI-spec .44 magnum and .45 Colt. While the .357's are also very strong, most people see it as excess because the .357 case simply doesn't hold enough of the slow burning powders to get a lot more out of it. The medium-frame Blackhawks and Vaqueros have sufficient strength for hot .357's. The .44 and .45 are well-served by the extra strength of the larger frame if they will be shot with super hot magnum loads. On the other hand, if only low-pressure cowboy or black-powder loads are to be shot, then the medium frame guns are lighter and handier for the job.
The steel grip frames on the New Vaqueros do add substantial weight compared to the aluminum grip frames on the Blackhawks and old Vaqueros. On the other hand, aluminum is kind of a Buck-Rogers, Space-Age metal that doesn't seem appropriate for what are essentially 1873 resto-mods. While the .357 might also seem very 20th century, it does have roots that go back to the 38's and the 1851 Navy that made the .36 caliber so popular. As it turns out, the New Vaqueros end up quite a bit heavier than Colts and closer Colt replicas, but they would seem to be more durable too.